1. Field of the Invention
The present invention relates to a manufacturing method of a semiconductor load board, and more particularly, to a manufacturing method of a semiconductor load board on which the width of the solder pads formed is smaller than or equal to the width of the opening of the dielectric layer formed.
2. The Prior Arts
FIG. 1 illustrates the cross sectional view of the semiconductor load board in prior arts. As shown in FIG. 1, the semiconductor load board 1 comprises a substrate 10, a plurality of connection pads 22, a patterned circuit layer 24, a dielectric layer 30, a plurality of solder pads 48, and a plurality of solders 58. The substrate 10 is made of polymer materials or ceramic materials, and the polymer materials comprise Bismaleimide Triazine (BT). The connection pads 22 and the patterned circuit layer 24 are located on the substrate 10, and are formed using a first conductive material comprising copper. The dielectric layer 30 is formed on the connection pads 22 and the patterned circuit layer 24, and has a plurality of openings 35 corresponding to the plurality of connection pads 22, wherein the openings 35 have a width reduced gradually toward the connection pads 22, and the minimum width is D1, and the maximum width is D2. The solder pads 48 are formed in the openings 35 corresponding to the connection pads 22 to fill up the openings 35. The solder pads 48 have a height higher than the height of the dielectric layer 30, and the width D6 of a portion higher than the dielectric layer 30 is wider than the maximum width D2 of the openings 35. The solder pads 48 are formed by a second conductive material which is copper or copper with nickel-gold or tin coating. The solders 58 are formed on each solder pad 48 respectively to cover the solder pad 48 for connecting to external circuits (not shown).
While the technology develops, the number of the chips loaded on the same semiconductor load board increases. The structure of the prior arts has a problem that the solder pads are too close to each other, and makes short-circuit failure and electrical interference more likely to occur. Therefore, a load board structure that can reduce the problems of the short-circuit failure and electrical interference, and the manufacturing method thereof is needed.